Nasolacrimal intubation with mitomycin c: Author reply

Abstract

We thank Drs Boboridis, Ziakas, and Georgiadis for their comments. As stated in the abstract, the purpose of our study was to determine if mitomycin C application during silicone intubation is an effective substitute for dacryocystorhinostomy (DCR) or Jones tube insertion. Regarding their question about the process of randomization, it was generated by a computer program. The small sample obviated the need to separate study groups by upper and lower canalicular obstruction. In addition, it should be kept in mind that the contribution of the upper and lower lacrimal drainage systems in patients with a tearing problem is often unclear.1Linberg J.V Moore C.A Symptoms of canalicular obstruction.Ophthalmology. 1988; 5: 1077-1079Abstract Full Text PDF Scopus (48) Google Scholar, 2Daubert J Nik N Chandeyssoun P.A el-Choufi L Tear flow analysis through the upper and lower systems.Ophthal Plast Reconstr Surg. 1990; 6: 193-196Crossref PubMed Scopus (14) Google Scholar, 3Meyer D.R Antonello A Linberg J.V Assessment of tear drainage after canalicular obstruction using fluorescein dye disappearance.Ophthalmology. 1990; 97: 1370-1374Abstract Full Text PDF PubMed Scopus (25) Google Scholar We also pointed out the risk of a type 2 statistical error. A pointed K-wire was used to overcome the obstruction because no known noninvasive technique exists. Patient 19 indeed had a 10-mm scar in the lacrimal system, and advancement of the K-wire was successful, without trauma. A new track was not created, and he responded well to silicone–mitomycin treatment. Two patients in the placebo group with intermittent post-treatment epiphora were not included in the statistical analysis. Although they reported symptoms of intermittent epiphora, no objective clinical findings were documented. Dacryocystorhinostomy was considered unnecessary in these 2 patients. The inclusion of these 2 patients in the data would have been scientifically unsound because of the equivocal outcomes. Three patients (10, 13, and 23) had DCR by the fourth month after treatment. As described in the “Surgical Technique” section, the silicone tube remained in place for 6 months if no contraindications existed. When necessary, however, we performed DCR or Jones tube insertion without delay, which was the case in these 3 patients. To clarify the circumstances of DCR in patients 2, 8, and 21: this was an intraoperative decision, although they had classic indications for Jones tube insertion before the silicone–mitomycin study procedure. As our study and Soll4Soll D.B Silicone intubation an alternative to dacryocystorhinostomy.Ophthalmology. 1978; 85: 1259-1266Abstract Full Text PDF PubMed Scopus (26) Google Scholar have shown, 53% to 60% of patients with classic indications for DCR or Jones tube insertion may be treated successfully with silicone intubation.